This invention relates to a decentered intraocular lens, and more particularly to such an artificial lens to correct high myopia of an intact natural lens in an eye having a decentered pupil. The artificial lens is implanted in the anterior chamber in front of the natural lens and centered relative to the pupil, its lens body having differentially sized haptics to insert it safely without damaging the natural lens and maintain it in pupil centered position, with its outer edge sufficiently masked by the iris to inhibit edge glare.
This invention is an improvement over applicant's earlier teaching in U.S. application Ser. No. 222,133 filed July 21, 1988, now U.S. Pat. No.4,871,363 the disclosure of which is hereby incorporated herein.
That earlier teaching concerns an intraocular lens, inserted via a corneal incision and implanted in the anterior chamber, e.g. to treat high myopia. The unit has a lens body centered by opposed leading and trailing haptics, each terminating in a transverse edge with a pair of laterally spaced contact lobes to engage tissue in the angle groove between the scleral spur and iris, per four point fixation technique, to seat the unit centered relative to the pupil and eye axis. The unit has a short edge trailing haptic for safe implanting via a minimum size incision without contacting the natural lens. On inserting the leading haptic and lens body, the trailing haptic is slightly pressed to clear the incision and be seated.
However, that earlier teaching does not concern the problem of implanting an intraocular lens in the anterior chamber of an eye having a decentered pupil, so that the centered lens body is decentered relative to the iris, and causes objectionable edge glare, as where the lens body is a high myopia corrective lens, i.e. having a thickened outer edge, which does not completely or at least not sufficiently overlap the iris, and thus permits light rays striking the lens body edge to produce edge glare transmitted to the retina.
U.S. Pat. No. 4,253,200 to Kelman shows a posterior chamber intraocular lens with a lens body and pair of haptics, one radially longer than the other, but they do not have opposing contact lobe pairs for four point fixation, nor is the lens body precisely decentered relative to the optical axis of the eye, or constructed to correct natural lens high myopia in an eye having a decentered pupil causing lens body edge glare. The unit replaces the natural lens, after its extracapsular removal, and is located behind the iris with the longer haptic seated in the ciliary sulcus and the shorter one seated in the capsular bag from which the natural lens has been removed.